Evaluating tolerance to calcareous soils in Vitis vinifera ssp sylvestris

We evaluate tolerance to soil lime in Vitis vinifera ssp. sylvestris to explore the physiological mechanisms involved in plant tolerance to calcareous soil conditions. The effects of soil CaCO3 content (0-60 %) on growth, photosynthetic performance and mineral nutrient content were analyzed in Vitis vinifera ssp. sylvestris from two populations, native to calcareous and non-calcareous soils, respectively, and in the lime-tolerant grapevine rootstock "41B". The reduction in relative growth rate of plants exposed to 20 and 40 % CaCO3 was around 70 % in the "41B" rootstock, whereas the reduction in wild grapevine plants from populations native to calcareous and non-calcareous soils was around 30 and 40 %, respectively. Wild grapevines showed a greater ability to maintain the integrity of their photosynthetic apparatus despite the nutritional disorders caused by lime-stress conditions in comparison to grapevine rootstock "41B". Plants from the population found in highly calcareous soil were capable of maintaining Fe uptake and translocation to leaves even under extremely high lime conditions (40 % CaCO3) and were more efficient in controlling leaf concentrations of the main macronutrients in comparison to wild grapevines from the other studied population. Variation in the maintenance of essential mineral nutrient status may be a crucial factor in plant tolerance to calcareous soil conditions.